The canine pancreas-duodenum has been perfused for 3 h with a membrane oxygenator, a pulsatile pump and a heat exchanger at a temperature of 37 °C. Among the criteria used in this study, the insulin output into the venous blood in response to glucose administration, as well as pancreas secretion after secretin stimulation were those found to be the most reliable indicators as to the viability of the pancreas. This is further supported by an average oxygen consumption of 0.77 ml O2/100 g at a constant flow of 80 ml/min and a perfusion pressure of 75 mm Hg. The pressure/flow relationship as for any other perfused organ was a safe indicator as to the viability of the perfused pancreas. The functional viability correlated with our anatomical findings.